CISCO CCNA Exam – Q182

Refer to the exhibit.
CISCO CCNA Exam – Q182

C-router is to be used as a “router-on-a-stick” to route between the VLANs. All the interfaces have been properly configured and IP routing is operational. The hosts in the VLANs have been configured with the appropriate default gateway. What is true about this configuration?

A.
These commands need to be added to the configuration:
C-router(config)# router eigrp 123
C-router(config-router)# network 172.19.0.0
B.
These commands need to be added to the configuration:
C-router(config)# router ospf 1
C-router(config-router)# network 172.19.0.0 0.0.3.255 area 0
C.
These commands need to be added to the configuration:
C-router(config)# router rip
C-router(config-router)# network 172.19.0.0
D.
No further routing configuration is required.

Correct Answer: D

Explanation:
Since all the same router (C-router) is the default gateway for all three VLANs, all traffic destined to a different VLA will be sent to the C-router. The C-router will have knowledge of all three networks since they will appear as directly connected in the routing table. Since the C-router already knows how to get to all three networks, no routing protocols need to be configured.

CISCO CCNA Exam – Q170

Which three elements must be used when you configure a router interface for VLAN trunking? (Choose three.)

A. one physical interface for each subinterface
B. one IP network or subnetwork for each subinterface
C. a management domain for each subinterface
D. subinterface encapsulation identifiers that match VLAN tags
E. one subinterface per VLAN
F. subinterface numbering that matches VLAN tags

Correct Answers: B,D,E

Explanation:
This scenario is commonly called a router on a stick.

CISCO CCNA Exam – Q132

Refer to the exhibit.
CISCO CCNA Exam – Q132

A network administrator is adding two new hosts to SwitchA. Which three values could be used for the configuration of these hosts? (Choose three.)

A. host A IP address: 192.168.1.79
B. host A IP address: 192.168.1.64
C. host A default gateway: 192.168.1.78
D. host B IP address: 192.168.1.128
E. host B default gateway: 192.168.1.129
F. host B IP address: 192.168.1.190

Correct Answers: A,C,F

Explanation:
It’s a “router-on-a-stick” configuration. Which means each host in the VLAN must corresponds with the VLAN configured on the sub-interfaces.
VLAN 10 is configured on fa0/0.10 and VLAN 20 on fa0/0.20. So each hosts in VLAN 10 must use fa0/0.10 IP address as their default gateway, each hosts must also be in the same subnet as fa0/0.10 IP – same with hosts in VLAN 20.
So find out the usable IP addresses on each sub-interfaces – for 192.168.1.78 /27: 192.168.1.65 – .94 and for 192.168.1.130 /26: 192.168.1.128 – .190.
Host A (using port 6 – VLAN 10) must use IP 192.168.1.79, default gateway 192.168.1.78.
Host B (using port 9 – VLAN 20) must use IP 192.168.1.190, default gateway 192.168.1.130.